Page 1 of 1

PNEU flags, PSA and CADC logic at high-G flight

Unread postPosted: 10 Oct 2021, 18:56
by serpent03
Hello guys! First post here, and I had a bit of a question that's been bugging me for a long time.

Why does the PNEU light come up when the F-16 is under high-G maneuvers?

After some research, it appears that PNEU flag comes up as a part of a secondary altimeter operation mode, under which pneumatically operated mechanical objects provid static pressure to update altitude.

Now taking a look at the air data system schematic, it looks like altimeter data is provided through both CADC(through the FCC), and through the PSA too, independently.

So here's the questions:
-Why does the jet switch to PNEU during high-G?
-Why does high-G matter enough to cause a shift? Can there be some sort of failure for CADC under Gs(this shouldn't matter right, as modern day INS/GPS combo works with lasers?)